BeatMaker (V. 1.3.2, Intua; $19.99) gets my vote as the most comprehensive music-production app on this platform. It turns your iPhone or iPod touch into a full-featured, loop-based, trigger pad-equipped production environment. It even works as a sampler and lets you edit the start and end points and place your samples — or imported WAV files — onto trigger pads. (File import/export is supported through the free BeatPack software for Mac and Windows.) It has two effects buses, a pattern-based sequencer and step sequencer, and a passel of included content kits from such artists as Richard Devine. It too requires some time to learn its UI, but it's surprisingly intuitive and powerful.

FEATURES, AT A GLANCE

16 sample-based trigger pads with multitouch support (up to five pads at once)
Low-latency playback and sample-accurate audio engine
Live pattern recording and arranging
Audio recording from microphone or headset
Step sequencer with different resolutions
Multitrack song sequencer
Export to WAV and MIDI Score
Sound library features breakbeat, drums and bass, dub, electronica, funk, hip-hop, jazz, rock and more
AIFF and WAV file support
Network-sharing capabilities via BeatPack
Two effects channels with four effects on each with Bypass control
Synchronized delays with feedback and wet/mix control
3-band EQ
Low/Hi/Bandpass filters

Find out more information about BeatMaker.